Engine starter



J1me 1945. J. w. FITZ GERALD 2,379,073

ENGINE STARTER Filed June 19. 1943 n "3W Juhn WF'uzEEra [do EC EAS ED Mr E F Patented June 26, 1945 ENGINE maria John W. Fitz Gerald, deceased, late of Milwaukee,

Wis., by Mary C. Fitz Gerald, executrix, Milwaukee, Wis., assignor to Briggs & Stratton Corporation, Milwaukee, Wis., a corporation of Delaware Application June 19, 1943, Serial No. 491,508 1 Claim. (01. 74-1) This invention relates to engine starters and has as its object the provision of a starter and a system of operating and controlling the same which is so designed as to eliminate the usual threaded connection and dependence upon inertia as in the conventional automatic starter and the overrunning clutch and system of levers on the manual type of starter.

To this end it is an object of this invention to provide a starter wherein the pinion is in mesh with the ring gear when the engine is idle and not in operation so that upon closure of the starter switch the motor merely takes up the cranking load.

Another object of this invention resides in the provision of means responsive to and operable by a function of the engine for retracting the pinion after the engine starts.

Another object of this invention is to provide a latch for releasably holding the pinion retracted and which is balanced against a spring tending to release the latch so that release of the latch and projection of the pinion into mesh with the ring gear can be set to occur as the engine is coming to rest to insure meshing of the pinion and ring gear.

With the above and other objects in view, which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claim, it being understood that such changes in the precise embodiment of the hereindis closed invention may be made as come within the scope of the claim.

The accompanying drawing illustrates one complete example of the physical embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a view partially in side elevation and partially in section illutstrating one adaptation of this invention and showing the parts in the positions they occupy when the engine is not in operation; and

Figure 2 is a View similar to Figure I but showing the parts in the positions they occupy when the engine is running.

Referring now particularly to the accompanying drawing, the numeral 5 designates the shaft of a starter motor upon which the starter mechanism, indicated generally by the numeral 6, is mounted.

The starter mechanism comprises a sleeve 1 fixed to the motor shaft and on which a pinion member 8 is slidably splined. Stops 9 and II] are secured to the opposite ends of the sleeve, the former being engageable by the pinion when in its operative driving position at which it meshes with the ring gear I I of an engine to be started, and the latter providing an abutment for a spring I2 which yieldingly urges the pinion member toward the stop 9 and into engagement with the engine ring gear.

The pinion member 8 has an enlarged portion I3 which constitutes a piston operating in a cylinder I4. The cylinder I4 is fixed to the hub I5 0f the starter motor which, being coaxial with the shaft, enables the cylinder and piston to have a close though free running fit.

A port I6 has a suction line I? connected thereto to connect the cylinder with the intake manifold so that the vacuum in the intake manifold is manifested in the cylinder I4 to retract the pinion member when the engine starts.

With the pinion member fully retracted as shown in Figure 2, a latch I8 snaps into an annular groove I9 to releasably hold the pinion member in its retracted position. The latch I8 is responsive to some function of the engine as, for instance, the pressure in the lubricating system. Hence, when the engine begins to operate and pressure obtains in the lubricating system, the latch I8 is potentially operative to snap into the groove I9 as soon as the pinion member is retracted sufficiently.

During stopping of the engine the diminishing oil pressure on the latch enables the latch spring 20 to retract the latch and free the pinion memher for projection back into mesh with the ring gear and as this occurs while the engine is coastconsequence meshing of the pinion with the ring gear is assured.

From the foregoing description, taken in connection with the accompanying drawing, it will be readily apparent to those skilled in the art that this invention provides a simple engine starter and manner of operating the same and that by virtue of its elimination of the usual screw threaded connection and dependence upon inertia, much of the difiiculty attending past engine starter construction is avoided.

It will also be readily apparent that although the pinion is retracted by engine suction in the embodiment of the invention illustrated, any other function of the engine may be substituted without deviating from the scope of this invenion.

What is claimed as the invention is:

In an engine starter system for starting an internal combustion engine having a ring gear and having an intake manifold in which vacuum is created by operation of the engine: a power haft; a pinion slidably splined to the 'power shaft and movable longitudinally to and from a position meshing with the ring gear; means yieldingly urging the pinion longitudinally into mesh with the ring gear; a cylinder and piston surroundin 10 the power shaft, the piston and pinion being fixed to each other; and means for connecting the cylinder with the engine intake pipe so that suction prevalent when the engine begins to operate under its own power retracts the pinion out of mesh with the ring gear.

MARY C. FI'IZ GERALD, Execut'ria: of the Estate of John W. Fitz Gerald,

Deceased. 

